Novel bisphosphite compounds and their metal complexes

ABSTRACT

A bisphosphite of the formula I  
                 
 
     wherein R 1 , R 2 , R 3  and R 4  are each hydrogen, an aliphatic, alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic, aromatic-aromatic, aliphatic-aromatic hydrocarbon group having from 1 to 50 carbon atoms, F, Cl, Br, I, —CF 3 , —OR 7 , —COR 7 , —CO 2 R 7 , —CO 2 M, —SR 7 , —SO 2 R 7 , —SOR 7 , —SO 3 R 7 , —SO 3 M, —SO 2 NR 7 R 8 , NR 7 R 8 , N═CR 7 R 8 , NH 2 , where R 1  to R 4  are identical or different and may be covalently linked to one another;  
     R 7  and R 8  are each hydrogen, a substituted or unsubstituted, aliphatic or aromatic hydrocarbon radical having from 1 to 25 carbon atoms, and may be identical or different;  
     M is an alkali metal, alkaline earth metal, ammonium or phosphonium ion;  
     Q is a divalent aliphatic, alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic, aliphatic-aromatic hydrocarbon radical having from 1 to 50 carbon atoms;  
     W and X are each an aliphatic, alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic, aromatic-aromatic, aliphatic-aromatic hydrocarbon radical having from 1 to 50 carbon atoms which may be identical or different or covalently linked to one another.

BACKGROUND OF THE INVENTION

[0001] 1. Field Of The Invention

[0002] The present invention relates to bisphosphites and their metalcomplexes, and the preparation and the use of the bisphosphites asligands in catalytic reactions.

[0003] 2. Description Of The Background

[0004] The reaction between olefin compounds, carbon monoxide andhydrogen in the presence of a catalyst to form aldehyde product havingone more carbon atom than the carbon atom content of the starting olefinis known as hydroformylation (the oxo process). The catalysts used inthese reactions are frequently compounds of transition metals of GroupVIII of the Periodic Table of the Elements, in particular compounds ofrhodium and of cobalt. In comparison with catalysis using cobaltcompounds, hydroformylation using rhodium compounds generally offers theadvantage of higher selectivity and is thus usually more economical. Inrhodium-catalyst hydroformylation, use is usually made of complexescomprising rhodium and preferably trivalent phosphorus compounds asligands. Examples of known ligands are compounds from the classes of thephosphines, phosphites and phosphonites. A good review of thehydroformylation of olefins may be found in B. CORNILS, W. A. HERRMANN,“Applied Homogeneous Catalysis with Organometallic Compounds” Vol. 1&2,VCH, Weinheim, New York, 1996.

[0005] Each catalyst system (cobalt or rhodium) has its specificadvantages. For this reason, different catalyst systems may be useddepending on the starting material and target product, as the followingexamples show. When rhodium and triphenylphosphine are employed,a-olefins can be hydroformylated at relatively low pressures. An excessof triphenylphosphine is generally used as phosphorus-containing ligand,and a high ligand/rhodium ratio is necessary to increase the selectivityof the reaction to the commercially desired n-aldehyde product.

[0006] U.S. Pat. No. 4,694,109 and 4,879,416 describe bisphosphineligands and their use in the hydroformylation of olefins at lowsynthesis gas pressures. Particularly in the hydroformylation ofpropane, ligands of this type achieve high activities and high n/iselectivities. WO 95/30680 discloses bidentate phosphine ligands andtheir use in catalysis, including hydroformylation reactions.Ferrocene-bridged bisphosphines are described as ligands forhydroformylation reactions in, for example, the U.S. Pat. Nos.4,169,861, 4,201,714 and 4,193,943.

[0007] The disadvantage of bidentate phosphine ligands is the relativelyhigh cost of preparing them. It is therefore often not economicallyviable to use such systems in industrial processes.

[0008] Rhodium-monophosphite complexes are suitable catalysts for thehydroformylation of branched olefins having internal double bonds, butthe selectivity to terminally hydroformylated compounds is low. EP 0 155508 discloses the use of bisarylene-substituted monophosphites in therhodium-catalyst hydroformylation of sterically hindered olefins, e.g.isobutene.

[0009] Rhodium-bisphosphite complexes catalyze the hydroformylation oflinear olefins having terminal and internal double bonds, formingpredominantly terminally hyroformylated products, while branched olefinshaving internal double bonds are reacted to only a small extent. Oncoordination to a transition metal center, these phosphites providecatalysts having increased activity, but the operating life of thesecatalysts systems is unsatisfactory because of, inter alia, thehydrolysis sensitivity of the phosphite ligands. Considerableimprovements have been achieved by use of substituted bisaryl diols asstarting materials for the phosphite ligands, as described in EP 0 214622 and EP 0 472 071. According to the literature, the rhodium complexesof these ligands are extremely active hydroformylation catalysts fora-olefins. U.S. Pat. Nos. 4,668,651, 4,748,261 and 4,885,401 describepolyphosphite ligands by means of which c-olefins and also 2-butene canbe converted highly selectively to the terminally hydroformylatedproducts. Bidentate ligands of this type have also been used for thehydroformylation of butadiene (U.S. Pat. No. 5,312,996).

[0010] Although the bisphosphites mentioned are very good complexingligands for rhodium hydroformylation catalysts, the need continues toexist for bisphosphites of improved effectiveness.

SUMMARY OF THE INVENTION

[0011] Accordingly, one object of the present invention is to provide abisphosphite ligand for the preparation of olefin hydroformylationcatalysts of improved effectiveness.

[0012] Briefly, this object and other objects of the present inventionas hereinafter will become more readily apparent can be attained by abisphosphite of the formula I:

[0013] wherein:

[0014] R¹, R², R³ and R⁴ are each hydrogen, an aliphatic, alicyclic,aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic,aromatic-aromatic, aliphatic-aromatic hydrocarbon radical having from 1to 50 carbon atoms, F, Cl, Br, I, —CF₃, —OR⁷, —COR⁷, —CO₂R⁷, —CO₂M,—SR⁷, —SO₂R⁷, —SOR⁷, -SO₃R⁷, —SO₃M, —SO₂NR⁷R⁸, NR⁷R⁸, N═CR⁷R⁸, NH₂,where R¹ to R⁴ are identical or different and may be covalently linkedto one another;

[0015] R⁷ and R⁸ are each hydrogen, a substituted or unsubstituted,aliphatic or aromatic hydrocarbon radical having from 1 to 25 carbonatoms, and may be identical or different;

[0016] M is an alkali metal, alkaline earth metal, ammonium orphosphonium ion;

[0017] Q is a divalent aliphatic, alicyclic, aliphatic-alicyclic,heterocyclic, aliphatic-heterocyclic, aromatic-aromatic, aromatic,aliphatic-aromatic hydrocarbon radical having from 1 to 50 carbon atoms;

[0018] W and X are each an aliphatic, alicyclic, aliphatic-alicyclic,heterocyclic, aliphatic-heterocyclic, aromatic, aromatic-aromatic,aliphatic-aromatic hydrocarbon radical having from 1 to 50 carbon atomswhich may be identical or different or covalently linked to one another.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] In formula I above, in any given embodiment of the bisphosphitecompound, two of the radicals R¹ to R⁴ in the formula I may bebenzofused, i.e. R¹ and R², R² and R³ or R³ and R⁴ may be linked to oneanother via an aromatic ring. It is thus possible to prepare threeisomers which can be used either separately or together as a ligandsystem. The bisphosphite of formula I can therefore also be in the formsillustrated by formulae II, III and IV as follows:

[0020] The definitions of radicals R¹ to R⁶ correspond to thedefinitions of R¹ to R⁴ defined for formula I. It is possible for theseradicals to be once again covalently linked to one another orbenzofused.

[0021] Specific embodiments of the bisphosphites of the invention arebisphosphites of the formulae V, VI and VII as follows:

[0022] wherein W and X are each an aliphatic, alicyclic,aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic,aromatic-aromatic, aliphatic-aromatic hydrocarbon radical having from 1to 50 carbon atoms, X and W may be identical or different or may becovalently linked to one another and R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸and Q are as defined above.

[0023] R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are each hydrogen or analiphatic, alicyclic, aliphatic-alicyclic, heterocyclic,aliphatic-heterocyclic, aromatic, aromatic-aromatic, aliphatic-aromatichydrocarbon radical having from 1 to 50 carbon atoms, F, Cl, Br, I,—CF₃, —OR²⁵, —COR²⁵, —CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃R²⁵,—SO₃M, —SO₂NR²⁵R²⁶, NR²⁵R²⁶, N═CR²⁵R²⁶, NH₂, where R⁹ to R¹⁶ areidentical or different and may be covalently linked to one another.

[0024] M is an alkali metal, alkaline earth metal, ammonium orphosphonium ion.

[0025] R²⁵ and R²⁶ may be identical or different and may each behydrogen or a substituted or unsubstituted, aliphatic or aromatichydrocarbon radical having from 1 to 25 carbon atoms.

[0026] Examples of Q are bivalent hydrocarbon radicals which may bealiphatic, alicyclic, aliphatic-alicyclic, heterocyclic,aliphatic-heterocyclic, aromatic, aromatic-aromatic oraliphatic-aromatic. Any ring system present may in turn be substitutedby the abovementioned hydrocarbon radicals. In open-chain structuralelements, one or more methylene groups may be replaced by oxygen and/orsulfur and/or NR¹ and/or NH and/or one or more CH groups may be replacedby nitrogen.

[0027] Q is preferably a bivalent radical containing aromatic groups. Qmay be, for example, a phenylene radical, a naphthalene radical, abivalent bisarylene radical or a bivalent radical of diphenyl ether.Furthermore, Q may have the structure —Ar—Z—Ar—. Here, Ar is amonocyclic or oligocyclic bivalent aromatic radical. Z is either adirect bond or a substituted or unsubstituted methylene group —CR²⁷R²⁸—,where R²⁷ and R²⁸ are hydrogen and/or aliphatic and/or aromatic radicalswhich have from 1 to 25 carbon atoms and may also contain heteroatoms.Furthermore, the radicals R²⁷ and R²⁸ may be linked to form one or morerings, i.e. be covalently bound.

[0028] Among the bisphosphites of the formulae I, II, III, IV, V, VI andVII, particularly preferred are those compounds in which radical Q is ahydrocarbon radical (bisarylene radical) of the formula VIII

[0029] where

[0030] R¹⁷, R¹⁸, R¹⁹, R²⁰, R²¹, R²², R²³ and R²⁴ are each hydrogen, analiphatic, alicyclic, aliphatic-alicyclic, heterocyclic,aliphatic-heterocyclic, aromatic-aromatic, aromatic, aliphatic-aromatichydrocarbon radical having from 1 to 50 carbon atoms, F, Cl, Br, I,—CF₃, —OR²⁵, —COR²⁵, —CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃R²⁵,—SO₃M, —SO₂NR²⁵R²⁶, NR²⁵R²⁶, N═CR²⁵R²⁶, NH₂, where R¹⁷ to R²⁴ areidentical or different and may be covalently linked to one another;

[0031] R²⁵ and R²⁶ are each hydrogen, a substituted or unsubstituted,aliphatic or aromatic hydrocarbon radical having from 1 to 25 carbonatoms;

[0032] M is an alkali metal, alkaline earth metal, ammonium orphosphonium ion, where the positions a and b are linkage points of thissubstituent in the structural element O—Q—O in the compounds of theformulae I to VII.

[0033] The present invention also provides bisphosphite-metal complexescomprising a metal of transition Group 4, 5, 6, 7 or 8 of the PeriodicTable of the Elements and one or more bisphosphites of the formulae I,II, III, IV, V, VI and VII. The substituents (R¹-R²⁶, Q, X, W) of thesebisphosphites are as defined above.

[0034] Representative examples of ligands of the formulae I, II, III,IV, V, VI and VII according to the present invention are presentedbelow, which compounds should not be taken to limit or restrict thescope of the present invention.

[0035] The bisphosphites of the invention can be prepared by a sequenceof reactions of phosphorus halides with alcohols orα-hydroxyarylcarboxylic acids in which the halogen atoms on thephosphorus are replaced by oxygen groups. The fundamental procedure isillustrated by a route to compounds of the formula V:

[0036] 1) A α-hydroxyarylcarboxylic acid is reacted with a phosphorustrihalide, preferably phosphorus chloride, in the presence of a base toform the intermediate A.

[0037] 2) A phosphorus trihalide, preferably phosphorus trichloride, isreacted with a diol or two molar equivalents of alcohol to form amonohalophosphite (intermediate B).

[0038] 3) A hydroxyl-substituted phosphite (intermediate C) is obtainedfrom the intermediate B by reaction of the intermediate with a diol(HO—Q—OH).

[0039] 4) The desired bisphosphite is obtained from the reaction ofintermediate A with product C.

[0040] The synthetic route is only one of many, but demonstrates thefundamental procedure. An alternative route is, for example, thereaction of intermediate A with the diol component and subsequentreaction with B to give the desired product.

[0041] Since the diols used and their downstream products are frequentlysolid, the reactions are generally conducted in solvents. Suitablesolvents are aprotic solvents which react neither with the diols norwith the phosphorus compounds and include tetrahydrofaran, diethyl etherand aromatic hydrocarbons such as toluene.

[0042] The reaction of phosphorus halides with alcohols forms hydrogenhalide which is sequestered by means of added bases. Examples of basesused for this purpose include tertiary amines such as triethylamine. Itis sometimes also useful to convert the alcohols into metal alkoxides,for example, by reaction with sodium hydride or butyllithium, prior tothe reaction.

[0043] The novel bisphosphites of the formulae I, II, III, IV, V, VI andVII are suitable building blocks for the preparation of complexes withmetals of transition Groups 4, 5, 6, 7 and 8 of the Periodic Table ofthe Elements. These complexes, especially those of metals of transitiongroup 8, can be used as catalysts for carbonylation reactions orhydroformylation reactions, e.g. for the hydroformylation ofC₂-C₂₅-olefins. The ligands have a high hydrolysis stability.Particularly when using rhodium as catalyst metal, high catalyticactivities are obtained in hydroformylation reactions. Because of theirhigh molecular weight, the bisphosphites of the invention have a lowvolatility. They can therefore easily be separated from the lessvolatile reaction products. They are sufficiently readily soluble incustomary organic solvents.

[0044] The invention also provides for the use of the bisphosphites orthe bisphosphite-metal complexes in processes for the hydroformylationof olefins, preferably those having from 2 to 25 carbon atoms, to formthe corresponding aldehydes.

[0045] Metals which are preferably used for preparing the catalyticallyactive metal complexes of the bisphosphites of the invention includerhodium, cobalt, platinum and ruthenium. The active catalyst is formedunder reaction conditions from the ligand according to the invention andthe metal. The ligands of the invention can be added in free form to thereaction mixture. It is also possible to use a transition metal complexcomprising one of the abovementioned bisphosphite ligands as precursorfor the actual catalytically active complex. The hydroformylationprocess can be conducted at stoichiometric amounts of metal tobisphosphite or using an excess of free bisphosphite ligands relative tometal containing reactant (e.g. from 1:1 to 200:1).

[0046] It is also possible for mixtures of various ligands, bothbisphosphites according to the invention, including the isomers of theformulae II to IV, and also other suitable phosphorus-containingligands, to be present in combination as free ligand components.

[0047] Suitable additional ligands present in the reaction mixtureinclude phosphines, phosphites, phosphonites and phosphinites. Specificexamples of such ligands are:

[0048] Phosphines: triphenylphosphine, tris(p-tolyl)phosphine,tris(m-tolyl)phosphine, tris(o-tolyl)phosphine,tris(p-methoxyphenyl)phosphine, tris(p-dinethylamino-phenyl)phosphine,tricyclohexylphosphine, tricyclopentylphosphine, triethylphosphine,tri-(1-naphthyl)phosphine, tribenzylphosphine, tri-n-butylphosphine,tri-t-butylphosphine.

[0049] Phosphites: trimethylphosphite, triethylphosphite, tri-n-propylphosphite, tri-i-propylphosphite, tri-n-butylphosphite, tri-i-butylphosphite, tri-t-butylphosphite, tris(2-ethylhexyl)phosphite,triphenylphosphite, tris(2,4-di-t-butylphenyl)phosphite,tris(2-t-butyl-4-methoxyphenyl)phosphite,tris(2-t-butyl-4-methylphenyl)phosphite, tris(p-cresyl) phosphite. Inaddition, sterically hindered phosphite ligands as described, interalia, in EP 155 508, U.S. Pat. Nos. 4,668,651; 4,748,261; 4,769,498;4,774,361; 4,835,299; 4,885,401, 5,059,710; 5,113,022; 5,179,055;5,260,491; 5,264,616; 5,288,918 and 5,360,938, EP 472 071, EP 518 241and WO 97/20795 are also suitable ligands.

[0050] Phosphonites: methyldiethoxyphosphine, phenyldimethoxyphosphine,phenyldiphenoxyphosphine, 2-phenoxy-2H-dibenz[c,e][1,2]oxaphosphorin andtheir derivatives in which the hydrogen atoms are wholly or partlyreplaced by alkyl and/or aryl radicals or halogen atoms, and ligands asare described in WO 98 43935, JP 09-268152 and DE 198 10 794 and in theGerman patent applications DE 199 54 721 and DE 199 54 510.

[0051] Customary phosphinite ligands are described, inter alia, in U.S.Pat. No. 5,710,344, WO 95 06627, U.S. Pat. No. 5,360,938 or JP 07082281.Examples include diphenyl(phenoxy)phosphine and its derivatives in whichthe hydrogen atoms are wholly or partly replaced by alkyl and/or arylradicals or halogen atoms, diphenyl(methoxy)phosphine anddiphenyl(ethoxy)phosphine. In general, from 1 to 500 mol, preferablyfrom 1 to 200 mol, more preferably from 3 to 50 mol, of the ligand ofthe invention are used per mole of Group VIII transition metal. Freshligand can be added to the reaction at any point in time in order tokeep the concentration of free ligand constant. The catalytic transitionmetal-bisphosphite complexes of the invention can be synthesized beforeuse. However, the catalytically active complexes are generally formed insitu in the reaction medium from a catalyst precursor and the presentbisphosphite ligand.

[0052] Precursors of the present catalyst include salts and complexes oftransition metals. Suitable examples include rhodium carbonyls, rhodiumnitrate, rhodium chloride, Rh(CO)₂(acac) (acac=acetylacetonate), rhodiumacetate, rhodium octanoate and rhodium nonanoate.

[0053] The concentration of the metal in the reaction mixture is in therange from 1 ppm to 1000 ppm, preferably in the range from 5 ppm to 300ppm.

[0054] The hydroformylation reactions conducted using the bisphosphitesof the invention or the corresponding metal complexes can be conductedby known methods as described, for example, in J. FALBE, “New Syntheseswith Carbon Monoxide”, Springer Verlag, Berlin, Heidelberg, New York,page 95 ff., (1980).

[0055] The reaction temperatures for a hydroformylation process usingthe bisphosphites of the invention or bisphosphite metal complexes ascatalyst are in the range from 40° C. to 180° C., preferably from 75° C.to 140° C. The pressure under which the hydroformylation occurs rangesfrom 1-300 bar of synthesis gas, preferably 15-64 bar. The molar ratioof hydrogen to carbon monoxide (H₂/CO) in the synthesis gas ranges from10/1 to 1/10, preferably from 1/1 to 2/1.

[0056] The catalyst or ligand is homogeneously dissolved in thehydroformylation mixture comprising starting material (olefins) andproducts (aldehydes, alcohols, high boilers formed in the process). Itis possible, if desired, to use an additional solvent.

[0057] The starting materials for the hydroformylation are monoolefinsor mixtures of monoolefins having from 2 to 25 carbon atoms and aterminal or internal C—C double bond. The olefins can be linear,branched or cyclic and may also have a plurality of olefinicallyunsaturated groups. Suitable examples include propene, 1-butene,cis-2-butene, trans-2-butene, isobutene, butadiene, mixtures ofC₄-olefins, 1- or 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene,3-methyl-1-butene, 1-, 2- or 3-hexene, the C₆-olefin mixtures formed inthe dimerization of propene (dipropene), 1-heptene, heptenes, 2- or3-methyl-1 -hexene, 1-octene, octenes, 2-methylheptenes,3-methylheptenes, 5-methyl-2-heptene, 6-methyl-2-heptene,2-ethyl-1-hexene, the isomeric C₈-olefin mixtures formed in thedimerization of butenes (dibutene), 1-nonene, nonenes, 2- or3-methyloctenes, the C₉-olefin mixtures formed in the trimerization ofpropene (tripropene), decenes, 2-ethyl-1-octene, dodecenes, theC₁₂-olefin mixture formed in the tetramerization of propene or thetrimerization of butenes (tetrapropene or tributene), tetradecene,hexadecenes, the C₁₆-olefin mixtures formed in the tetramerization ofbutenes (tetrabutene) and also olefin mixtures prepared byco-oligomerization of olefins having different numbers of carbon atomspreferably from 2 to 4), if desired after fractional distillation toseparate them into fractions having the same number of carbon atoms or asimilar number of carbon atoms. It is likewise possible to use olefinsor olefin mixtures produced by Fischer-Tropsch synthesis, and alsoolefins which are obtained by oligomerization of ethene or can beproduced via methathesis reactions or telomerization reactions.

[0058] Preferred starting materials include propene, 1-butene, 2-butene,1-hexene, 1-octene, dimers and trimers of butene (dibutene, di-n-butene,diisobutene, tributene) and a-olefins in general.

[0059] The hydroformylation reaction can be conducted continuously orbatchwise. Examples of industrial apparatuses are stirred vessels,bubble columns, jet reactors, tube reactors and loop reactors, which maybe cascaded and/or provided with internals.

[0060] The reaction can be conducted in a single step or in a pluralityof steps. The aldehyde compounds formed and the catalyst can beseparated by a conventional method such as fractionation. This can, forexample, be carried out industrially by means of a distillation, bymeans of a falling film evaporator or by means of a thin filmevaporator. This is particularly applicable when the catalyst isseparated as a solution in a high-boiling solvent from the lower-boilingproduct. The catalyst solution which has been separated can be used forfurther hydroformylation. When using lower olefins, e.g. propene,butene, pentene, it is also possible for the products to be dischargedfrom the reactor in gaseous form.

[0061] Having generally described this invention, a furtherunderstanding can be obtained by reference to certain specific exampleswhich are provided herein for purposes of illustration only and are notintended to be limiting unless otherwise specified.

EXAMPLES

[0062] All preparations were conducted under protective gas usingstandard Schlenk techniques. The solvents were dried over suitabledesiccants before use.

[0063] 2-Chloro-1,3-dioxa-2-phosphaanthracen-4-one employed in thesynthesis of bisphosphite compounds was synthesized by the methoddescribed in the literature at (BE 667036, Farbwerke Hoechst AG, 1966;Chem. Abstr. 65 (1966) 13741d).3-Chloro-2,4-dioxa-3-phosphaphenanthren-1-one was obtained in ananalogous way. 2-Chloro-2,3-dioxa-2-phosphanaphthalen-4-one (van Boom'sReagenz) is commercially available.

Example 1

[0064] Synthesis of the Precursors C-1 and C-2

[0065] Precursor C-1

[0066] A solution of 0.93 g of PCl₃ (6.75 mmol) in 10 ml of THF wasadded dropwise at 0° C. to a solution of 2.42 g of2,2′-bis(6-tert-butyl-1-hydroxy-4-methoxyphenyl) (6.75 mmol) and 1.6 molof pyridine in 22 ml of THF. After stirring at 25° C. for 4 hours, thesolvent is removed under reduced pressure. Addition of 40 ml of diethylether, filtration and evaporation under reduced pressure gives 2.8 g(98%) of spectroscopically pure chlorophosphorous ester of2,2′-bis(6-tert-butyl-1-hydroxy-4-methoxyphenyl): ³¹P-NMR (CD₂Cl₂) δ172.7 ppm. 2.8 g of this chloroester (6.62 mmol) in 20 ml of THF isadded at room temperature to a monolithium phenoxide solution obtainedat −20° C. from 2.37 g of2,2′-bis(6-tert-butyl-1-hydroxy-4-methoxyphenyl) (6.62 mmol) in 30 ml ofTHF and 20.7 ml of a 0.32 M hexane solution of n-butyllithium (6.62mmol). After 24 hours, the mixture is evaporated under reduced pressure.Addition of 40 ml of methylene chloride, filtration and removal of thesolvent under reduced pressure give 4.6 g (93%) of highly viscousproduct.

[0067] Analysis (calc. for C₄₄H₅₇O₈P=744.9 g/mol) C, 70.35 (70.95); H,7.86 (7.71). ³¹P-NMR (CD₂Cl₂) δ 140.7 ppm. ¹H-NMR (CD₂Cl₂) δ 1.43 (s,9H); 1.56 (s, 9H); 1.63 (s, 9H); 1.67 (s, 9H); 4.01 (s, 3H); 4.03 (s,6H); 4.05 (s, 3H); 5.42 (s, 1H); 6.7 . . . 7.3 (m, 8H) ppm. FAB MS: m/e745 (37%), M⁺); 387 (100%,M⁺-2,2′-bis(6-tert-butyl-1-hydroxy-4-methoxyphenyl). IR (CHCl₃, 0.1 mmCaF₂), ν(OH)=3549 cm⁻¹.

[0068] Precursor C-2

[0069] The synthesis is carried out in a manner analogous to thepreparation of C-1. The chlorophosphite diester is obtained in avirtually quantitative yield (98.4%, ³¹P NMR, CD₂Cl₂ δ 172.0). For thesecond step of the reaction sequence, this chlorophosphite diester (10.7g, 22.5 mmol) is reacted with the product from 1.6 M butyllithiumsolution in hexane (14.1 ml) and the corresponding dihydroxybiphenylcompound. After removal of the solvent, the residue is extracted anumber of times with hot hexane. The product crystallizes from thecombined hexane fractions and is isolated and dried under reducedpressure. Yield: 76.4%

[0070] Analysis (calc. for C₅₆H₈₁O₄P=849.23 g/mol) C, 78.78 (79.20); H,9.95 (9.61). ³¹P-NMR (CD₂Cl₂) δ 142.3 ppm. ¹H-NMR (CD₂Cl₂) δ 0.98 (s,9H); 1.15 (s, 9H); 1.21 (s, 9H); 1.22 (s, 9H); 1.23 (s, 9H); 1.24 (s,9H); 1.30 (s, 9H); 1.36 (s, 9H); 5.35 (s, 1H); 6.99 (d, 1H); 7.01 (d,1H); 7.05 (d, 1H); 7.06 (d, 1H); 7.26 (d, 2H); 7.32 (d, 1H); 7.36 (d,1H) ppm.

Example 2

[0071] Synthesis of Ligand 2-a

[0072] A 9.5 ml amount of a 0.32M solution of n-butyllithium (3.04 mmol)is added dropwise at −20° C. to a solution of 2.27 g of C-1 (3.04 mmol)in 24 ml of THF while stirring. After warming to room temperature, themixture is firstly stirred for another 30 minutes and the resultingmixture is then added to 22 ml of a 0.138 M solution of2-chloro-1,3-dioxa-2-phosphaanthracen-4-one (3.04 mmol) in THF. Thereaction mixture is stirred at 25° C. for 4 hours, the solvent isremoved under reduced pressure and the syrup-like residue is stirred for2 hours with 60 ml of hexane. The mixture is filtered, and the filtercake is washed with 2×7 ml of hexane and extracted by back distillationof hexane from the filtrate. Storage of the mother liquor for 3 days at5° C. gives 0.828 g of pure solid. Additional extraction of the filtercake from the hexane extraction with 35 ml of boiling diethyl ethergives, after reduction of the volume of the filtrate to 50% and storageat 5° C., 0.6 g of product. Total yield: 1.428 g=49%. Analysis (calc.for C₅₅H₆₂O₁₁P₂=961.03 g/mol) C, 68.69 (68.74); H, 6.73 (6.50); P, 6.41(6.45)%.³¹P-NMR (CD₂Cl₂): δ 118.1; 119.1; 139.0; 140.2. ¹H-NMR (CD₂Cl₂):δ 1.15 . . . 1.44 (36H); 3.81 . . . 3.93 (12H); 6.57 . . . 8.71 (14H).FAB-MS: m/e 961 (30%, M⁺); 745 (31%); 727 (97%); 387 (100%).

Example 3

[0073] Synthesis of Ligand 3-a

[0074] The P—Cl compound used is3-chloro-2,4-dioxa-3-phosphaphenanthren-1-one. The synthesis isperformed starting from 2.31 g of C-1 (3.10 mmol) up to the extractionof the filter cake with backdistilled hexane from the filtrate in amanner analogous to the preparation of 2-a. Subsequent storage of thissolution at 5° C. initially gives 0.90 g, after reduction of the volumeto half, a further 1.36 g, of product; total yield: 2.26 g=75%. Analysis(calc. for C₅₅H₆₂O₁₁P₂=961.03 g/mol) C, 69.42 (68.74); H, 7.16 (6.50);P, 5.98 (6.45)%.³¹P-NMR (CD₂Cl₂): δ 120.3; 121.1; 139.7; 140.7. ¹H-NMR(CD₂Cl₂): 0.87 . . . 1.40 (36H); 3.75 . . . 3.88 (12H); 6.63 . . . 8.17(14H); Cl-MS: m/e 962 (31%, M-H⁺); 745 (100%); 405 (90%); 387 (80%).

Example 4

[0075] Synthesis of Ligand 6-a

[0076] The P—Cl compound is2-chloro-1,3-dioxa-2-phosphanaphthalen-4-one. The synthesis is conductedstarting from 6.86 g of C-1 up to the extraction of the filter cake in amanner analogous to the preparation of 2-a. The extraction is conductedusing hot hexane and using diethyl ether. Reduction of the amount ofsolvent to one third and subsequent storage of this solution at −20° C.gives the product in a yield of 54%. ³¹P-NMR (CD₂Cl₂): 119.2 (m); δ119.8 (m); 139.5 (m); 140.1 (m); ¹H-NMR (CD₂Cl₂): 1.02 . . . 1.26 (36H);3.67 . . . 3.74 (12H); 6.43 . . . 7.99 (12H). FAB-MS: m/e 911 (100%,M⁺), 744 (18%), 387 (13%).

Example 5

[0077] Synthesis of Ligand 6-b

[0078] The P—Cl compound used is2-chloro-1,3-dioxa-2-phosphanaphthalen-4-one. The synthesis is conductedstarting from 4.93 g of C-2 in a manner analogous to the synthesis ofcompound 2-a. Total yield: 50.4%. Analysis (calc. for C₆₃H₈₄O₇P₂=1015.30g/mol) C, 74.86 (74.53); H, 8.43 (8.34). ³¹P-NMR (CD₂Cl₂): δ 118.5,119.7, 142.0, 142.8; ¹H-NMR (CD₂Cl₂): 0.90 . . . 1.36 (72H); 6.74 . . .7.90 (12H); FAB-MS: m/e 1015 (7%, M+), 832 (100%), 439 (70%).

Example 6

[0079] Synthesis of Ligand 2-b

[0080] The P—Cl compound used is2-chloro-1,3-dioxa-2-phosphaanthracen-4-one. The synthesis is conductedstarting from 5.07 g of C-2 in a manner analogous to the preparation of2-a. Yield: 73%. Analysis (calc. for C₆₇H₈₆O₇P₂=1065.36 g/mol) C, 75.24(75.54); H, 8.16 (8.14). ³¹P-NMR (CD₂Cl₂): δ 117.8, 118.9, 142.1, 142.9;ratio of the diastereomers=1.3:1. ¹H-NMR (CD₂Cl₂): 0.99 . . . 1.35(72H); 6.95 . . . 8.55 (14H). FAB-MS: m/e 1064 (18%, M-H). 831 (100%),439 (78%).

Examples 7 and 8

[0081] Hydroformylation of 1-Octene

[0082] The experiments were conducted in a 200 ml stainless steelautoclave from Buddeberg, Marnheim, which was fitted with a spargingstirrer, pressure pipette and pressure regulator, was located in an oilbath thermostat and had been charged under protective gas. To minimizethe influence of moisture and oxygen, the toluene used as solvent wasdried by means of sodium cetyl and distilled under argon. The I-octeneused as substrate was refluxed over sodium for a number of hours anddistilled under argon.

[0083] The autoclave was charged with 27 ml of toluene in which 5.456mg=0.0176 mmol of [acacRh(COD)] and 0.088 mmol of the respective ligandhad been dissolved. The molar ratio of Rh/P was thus 1:10. 24 ml=about16.8 g (149.3 mmol) of 1-octene were placed in the pressure pipette overthe reactor. The ratio of Rh/1-octene was thus about 1:8500. Reactor andpressure pipette were pressurized via a bypass in parallel to thepressure regulation section with 33 bar of CO/H₂ (1:1; synthesis gas) ata set pressure of 50 bar and with thirteen bar of CO/H₂ at a setpressure of 20 bar, and the contents of the reactor were heated to 80 or100° C. while stirring magnetically by means of the sparging stirrer at1500 min⁻¹. After reaching the set temperature, the pressure wasincreased to 47 bar (17 bar) and the olefin mixture was injected fromthe pressure pipette into the reactor using a pressure of 55 bar (25bar). An initial reaction pressure of 49.6 bar (19.2 bar) wasestablished. After immediately regulating the pressure manually to 50bar (20 bar), the bypass was closed and the pressure was kept constantover the entire reaction time by means of the pressure regulator. Theexperiment was stopped by forcible cooling after the predeterminedreaction time had expired. The reaction solution was removed underprotective gas and analyzed by gas chromatography.

[0084] The following table reports the results obtained using theindividual ligands. Temp. p t Yield Proportion of Example Ligand [° C.][bar] [h] [%] nonanal [%] 7 2-a 100 20 3 81 79.0 8 3-a 100 20 3 79 83.8

Examples 9-19

[0085] Hydroformylation of a Mixture of 1-Octene, 2-Octene, 3-Octene and4-Octene

[0086] The experiments were conducted in a 200 ml stainless steelautoclave from Buddeberg, Mannheim, which was fitted with a spargingstirrer, pressure pipette and pressure regulator and located in an oilbath thermostat. The reactant was charged under protective gas. Tominimize the influence of moisture and oxygen, the toluene used assolvent was dried by means of sodium cetyl and distilled under argon.The octene isomer mixture used as substrate was refluxed over sodium fora number of hours and distilled under argon. Composition: 1-octene,3.3%; cis+trans-2-octene, 48.5%; cis+trans-3-octene, 29.2%;cis+trans-4-octene, 16.4%; branched C₈-olefins, 2.6%.

[0087] The autoclave was charged with 41 ml of toluene in which 18.75mg=0.0604 mmol of [acacRh(COD)], the respective bidentate ligand and, ifrequired, the coligand depicted below had been dissolved. The ratio ofRh/bidentate ligand (ligand)/ether phosphonite (coligand) is shown inthe table. 15 ml=10.62 g (94.63 mmol) of octenes were placed in thepressure pipette over the reactor. The ratio of Rh/octenes was thusabout 1:1570. Reactor and pressure pipette were pressurized via a bypassin parallel to the pressure regulation section with 13 bar of CO/H₂(1:1; synthesis gas) and the contents of the reactor were heated to 130°C. while stirring magnetically by means of the sparging stirrer at 1500min⁻¹. After reaching the set temperature, the pressure was increased to17 bar and the olefin mixture was injected from the pressure pipetteinto the reactor using a pressure of 25 bar. An initial reactionpressure of 19.2 bar was established. After immediately regulating thepressure manually to 20 bar, the bypass was closed and the pressure waskept constant over the entire reaction time by means of the pressureregulator. The experiment was stopped by forcible cooling after threehours. The reaction solution was taken out under protective gas andanalyzed by gas chromatography.

[0088] The co-ligand used was:

[0089] The following table reports the results obtained using theindividual ligands. Propor- tion of Ligand/- T Rh/Lig/CoLig/olefin tYield nonanal Example coligand [° C.] [mol/mol/mol/mol] [h] [%] [%]  92-a 130 1/5/0/1570 3 95 64.2 10 2-b 130 1/5/0/1570 3 93 67.9 11 3-a 1301/5/0/1570 3 96 69.0 12 6-a 130 1/5/0/1570 3 94 63.9 13 6-b 1301/5/0/1570 3 95 67.3 14 2-a/CL-1 130 1/2.5/5/1570 3 92 63.5 15 3-a/CL-1130 1/2.5/5/1570 3 93 67.8 16 6-a/CL-1 130 1/2.5/5/1570 6 98 63.0 17^(#)3-a 130 1/5/0/15700 6 74 69.5 18^(#) 6-a 130 1/5/0/15700 6 83 64.119^(#) 6-b 130 1/5/0/15700 6 66 69.0

Examples 20-25

[0090] Hydroformylation of Technical-Grade Di-N-Butene

[0091] The experiments were conducted by a method analogous to Examples9-19 using 15 ml=10.70 g (95.34 mmol) of a mixture of isomeric octenes(double bond isomers and skeletal isomers) obtained by dimerization ofn-butenes. The following Table reports both results obtained using purebidentate ligands and results obtained using a mixture of bidentateligand/co-ligand CL-1. Propor- tion of Ligand/- T Rh/Lig/CoLig/olefin tYield nonanal Example coligand [° C.] [mol/mol/mol/mol] [h] [%] [%] 202-a 130 1/5/0/1578 6 59 63.2 21 2-a/CL-1 130 1/2.5/5/1578 6 57 63.0 223-a 130 1/5/0/1578 6 56 65.7 23 3-a/CL-1 130 1/2.5/5/1578 6 60 65.4 246-a 130 1/5/0/1578 6 56 63.1 25 6-a/CL-1 130 1/2.5/5/1578 6 58 62.3

[0092] The disclosure of German priority Application No. 100 53 272.1filed Oct. 27, 2000 is hereby incorporated by reference into the presentapplication.

[0093] Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

What is claimed as new and is intended to be secured by Letters Patentis:
 1. A bisphosphite of formula I

wherein R¹, R², R³ and R⁴ are each hydrogen, an aliphatic, alicyclic,aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic,aromatic-aromatic, aliphatic-aromatic hydrocarbon group having from 1 to50 carbon atoms, F, Cl, Br, I, —CF₃, —OR⁷, —COR⁷, —CO₂R⁷, —CO₂M, —SR⁷,—SO₂R⁷, —SOR⁷, —SO₃R⁷, —SO₃M, —SO₂NR⁷R⁸, NR⁷R⁸, N═CR⁷R⁸, NH₂, where R¹to R⁴ are identical or different and may be covalently linked to oneanother; R⁷ and R⁸ are each hydrogen, a substituted or unsubstituted,aliphatic or aromatic hydrocarbon radical having from 1 to 25 carbonatoms, and may be identical or different; M is an alkali metal, alkalineearth metal, ammonium or phosphonium ion; Q is a divalent aliphatic,alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic,aromatic, aliphatic-aromatic hydrocarbon radical having from 1 to 50carbon atoms; W and X are each an aliphatic, alicyclic,aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic,aromatic-aromatic, aliphatic-aromatic hydrocarbon radical having from 1to 50 carbon atoms which may be identical or different or covalentlylinked to one another.
 2. A bisphosphite of formula II, III or IV

wherein R¹, R², R³, R⁴, R⁵ and R⁶ are each hydrogen, an aliphatic,alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic,aromatic, aromatic-aromatic, aliphatic-aromatic hydrocarbon radicalhaving from 1 to 50 carbon atoms, F, Cl, Br, I, —CF₃, —OR⁷, —COR⁷,—CO₂R⁷, —CO₂M, —SR⁷, —SO₂R⁷, —SOR⁷, —SO₃R⁷, —SO₃M, —SO₂NR⁷R⁸, NR⁷R⁸,N═CR⁷R⁸, NH₂, where R¹ to R⁶ are identical or different; R⁷ and R⁸ areeach hydrogen, a substituted or unsubstituted, aliphatic or aromatichydrocarbon radical having from 1 to 25 carbon atoms, and may beidentical or different; M is an alkali metal, alkaline earth metal,ammonium or phosphonium ion; Q is a divalent aliphatic, alicyclic,aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic,aliphatic-aromatic hydrocarbon radical having from 1 to 50 carbon atoms;and W and X are each an aliphatic, alicyclic, aliphatic-alicyclic,heterocyclic, aliphatic-heterocyclic, aromatic, aromatic-aromatic,aliphatic-aromatic hydrocarbon radical having from 1 to 50 carbon atomswhich may be identical or different or covalently linked to one another.3. A bisphosphite as claimed in claim 1, wherein W and X are eachaliphatic, alicyclic, aliphatic-alicyclic, heterocyclic,aliphatic-heterocyclic, aromatic, aromatic-aromatic, aliphatic-aromatichydrocarbon radicals having from 1 to 50 carbon atoms which arecovalently linked as in formula V

wherein R¹, R², R³, R⁴ and Q have the meanings and provisos stated inclaim
 1. 4. A bisphosphite as claimed in claim 1, wherein W and X areeach aromatic hydrocarbon radicals having from 1 to 50 carbon atomswhich are covalently linked as in formula VI

wherein R⁹, R¹⁰, R¹¹, R¹², R¹³ and R¹⁴ are each hydrogen, an aliphatic,alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic,aromatic, aromatic-aromatic, aliphatic-aromatic hydrocarbon radicalhaving from 1 to 50 carbon atoms, F, Cl, Br, I, —CF₃, —OR²⁵, —COR²⁵,—CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃R²⁵, —SO₃M, —SO₂NR²⁵R²⁶,NR²⁵R²⁶, N═CR²⁵R²⁶, NH₂, where R⁹ to R¹⁴ are identical or different andmay be covalently linked to one another, R²⁵ and R²⁶ are each hydrogenor a substituted or unsubstituted, aliphatic or aromatic hydrocarbonradical having from 1 to 25 carbon atoms, and may be identical ordifferent, M is an alkali metal, alkaline earth metal, ammonium orphosphonium ion and R¹, R², R³, R⁴ and Q have the meanings and provisosstated in claim
 1. 5. A bisphosphite as claimed in claim 1, wherein Wand X are each aromatic hydrocarbon radicals having from 1 to 50 carbonatoms which are covalently linked as in formula VII

where R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are each hydrogen, analiphatic, alicyclic, aliphatic-alicyclic, heterocyclic,aliphatic-heterocyclic, aromatic, aromatic-aromatic, aliphatic-aromatichydrocarbon radical having from 1 to 50 carbon atoms, F, Cl, Br, I,—CF₃, —OR²⁵, —COR²⁵, —CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃R²⁵,—SO₃M, —SO₂NR²⁵R²⁶, NR²⁵R²⁶, N═CR²⁵R²⁶, NH₂, where R⁹ to R¹⁶ areidentical or different and may be covalently linked to one another, R²⁵and R²⁶ are each hydrogen or a substituted or unsubstituted, aliphaticor aromatic hydrocarbon radical having from 1 to 25 carbon atoms, andmay be identical or different, M is an alkali metal, alkaline earthmetal, ammonium or phosphonium ion and R¹, R², R³, R⁴ and Q have themeanings and provisos stated in claim
 1. 6. A bisphosphite as claimed inclaim 2, wherein W and X are each aliphatic, alicyclic,aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic,aromatic-aromatic, aliphatic-aromatic hydrocarbon radicals having from 1to 50 carbon atoms which are covalently linked as in formula V

wherein R¹, R², R³, R⁴ and Q have the meanings and provisos stated inclaim
 1. 7. A bisphosphite as claimed in claim 2, wherein W and X areeach aromatic hydrocarbon radicals having from 1 to 50 carbon atomswhich are covalently linked as in formula VI

wherein R⁹, R¹⁰, R¹¹, R¹², R¹³ and R¹⁴ are each hydrogen, an aliphatic,alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic,aromatic, aromatic-aromatic, aliphatic-aromatic hydrocarbon radicalhaving from 1 to 50 carbon atoms, F, Ca, Br, I, —CF₃, —OR²⁵, —COR²⁵,—CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃R²⁵, —SO₃M, —SO₂NR²⁵R²⁶,NR²⁵R²⁶, N═C²⁵R²⁶, NH₂ where R⁹ to R¹⁴ are identical or different andmay be covalently linked to one another, R²⁵ and R²⁶ are each hydrogenor a substituted or unsubstituted, aliphatic or aromatic hydrocarbonradical having from 1 to 25 carbon atoms, and may be identical ordifferent, M is an alkali metal, alkaline earth metal, ammonium orphosphonium ion and R¹, R², R³, R⁴ and Q have the meanings and provisosstated in claim
 1. 8. A bisphosphite as claimed in claim 2, wherein Wand X are each aromatic hydrocarbon radicals having from 1 to 50 carbonatoms which are covalently linked as in formula VII

where R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are each hydrogen, analiphatic, alicyclic, aliphatic-alicyclic, heterocyclic,aliphatic-heterocyclic, aromatic, aromatic-aromatic, aliphatic-aromatichydrocarbon radical having from 1 to 50 carbon atoms, F, Cl, Br, I,—CF₃, —OR²⁵, —COR²⁵, —CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃R²⁵,—SO₃M, —SONR²⁵R²⁶, NR²⁵R²⁶, N═CR²⁵R²⁶, NH₂, where R⁹ to R¹⁶ areidentical or different and may be covalently linked to one another, R²⁵and R²⁶ are each hydrogen or a substituted or unsubstituted, aliphaticor aromatic hydrocarbon radical having from 1 to 25 carbon atoms, andmay be identical or different, M is an alkali metal, alkaline earthmetal, ammonium or phosphonium ion and R¹, R², R³, R⁴ and Q have themeanings and provisos stated in claim
 1. 9. A bisphosphite as claimed inclaim 1, wherein Q is a hydrocarbon radical of the

where R¹⁷, R¹⁸, R¹⁹, R²⁰, R²¹, R²², R²³ and R²⁴ are each hydrogen, analiphatic, alicyclic, aliphatic-alicyclic, heterocyclic,aliphatic-heterocyclic, aromatic, aromatic-aromatic, aliphatic-aromatichydrocarbon radical having from 1 to 50 carbon atoms, F, Cl, Br, I,—CF₃, —OR²⁵, —COR²⁵, —CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃R²⁵,—SO₃M, —SO₂NR²⁵R²⁶, NR²⁵R²⁶, N═CR²⁵R²⁶, NH₂, where R¹⁷ to R²⁴ areidentical or different and may be covalently linked to one another, R²⁵and R²⁶ is hydrogen or a substituted or unsubstituted, aliphatic oraromatic hydrocarbon radical having from 1 to 25 carbon atoms, M is analkali metal, alkaline earth metal, ammonium or phosphonium ion, andpositions a and b are linkage points.
 10. A bisphosphite-metal complexcomprising a metal of transition Group 4, 5, 6, 7 or 8 of the PeriodicTable of the Elements and one or more bisphosphites of the formula I

wherein R¹, R², R³ and R⁴ are each hydrogen, an aliphatic, alicyclic,aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic,aromatic-aromatic, aliphatic-aromatic hydrocarbon radical having from 1to 50 carbon atoms, F, Cl, Br, I, —CF₃, —OR⁷, —COR⁷, —CO₂R⁷, —CO₂M,—SR⁷, —SO₂R⁷, —SOR⁷, —SO₃R⁷, —SO₃M, —SO₂NR⁷R⁸, NR⁷R⁸, N═CR⁷R⁸NH₂, whereR¹ to R⁴ are identical or different and may be covalently linked to oneanother, R⁷ and R⁸ are each hydrogen or a substituted or unsubstituted,aliphatic or aromatic hydrocarbon radical having from 1 to 25 carbonatoms, and may be identical or different, M is an alkali metal, alkalineearth metal, ammonium or phosphonium ion, Q is a divalent aliphatic,alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic,aromatic, aromatic-aromatic, aliphatic-aromatic hydrocarbon radicalhaving from 1 to 50 carbon atoms, W and X is an aliphatic, alicyclic,aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic,aliphatic-aromatic hydrocarbon radical having from 1 to 50 carbon atomswhich may be identical or different or covalently linked to one another.11. A bisphosphite-metal complex comprising a metal of transition Group4, 5, 6, 7 or 8 of the Periodic Table of the Elements and one or morebisphosphites of the formulae II, III and/or IV.

wherein R¹, R², R³, R⁴, R⁵ and R⁶ are each hydrogen, an aliphatic,alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic,aromatic, aromatic-aromatic, aliphatic-aromatic hydrocarbon radicalhaving from 1 to 50 carbon atoms, F, Cl, Br, I, —CF₃, —OR⁷, —COR⁷,—CO₂R⁷, —CO₂M, —SR⁷, —SO₂R⁷, —SOR⁷, —SO₃R⁷, —SO₃M, —SO₂NR⁷R⁸, NR⁷R⁸,N═CR⁷R⁸, NH₂, where R¹ to R⁶ are identical or different, R⁷ and R⁸ areeach hydrogen or a substituted or unsubstituted, aliphatic or aromatichydrocarbon radical having from 1 to 25 carbon atoms, and may beidentical or different, M is an alkali metal, alkaline earth metal,ammonium or phosphonium ion, Q is a divalent aliphatic, alicyclic,aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic,aromatic-aromatic, aliphatic-aromatic hydrocarbon radical having from 1to 50 carbon atoms, W and X are each an aliphatic, alicyclic,aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic, aromatic,aliphatic-aromatic hydrocarbon radical having from 1 to 50 carbon atomswhich may be identical or different or covalently linked to one another.12. A bisphosphite-metal complex as claimed in claim 10, wherein W and Xare aliphatic, alicyclic, aliphatic-alicyclic, heterocyclic,aliphatic-heterocyclic, aromatic, aromatic-aromatic, aliphatic-aromatichydrocarbon radicals having from 1 to 50 carbon atoms which arecovalently linked as in formula V

and R¹, R², R³, R⁴ and Q have the meanings and provisos stated in claim7.
 13. A bisphosphite-metal complex as claimed in claim 10, wherein Wand X are each a aromatic hydrocarbon radical having from 1 to 50 carbonatoms which is covalently linked as in formula VI

wherein R⁹, R¹⁰, R¹¹, R¹², R¹³ and R¹⁴ are each hydrogen, an aliphatic,alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic,aromatic, aromatic-aromatic, aliphatic-aromatic hydrocarbon radicalhaving from 1 to 50 carbon atoms, F, Cl, Br, I, —CF₃, —OR²⁵, —COR²⁵,—CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃M, —SO₂NR²⁵R²⁶, NR²⁵R²⁶,N═CR²⁵R²⁶, NH₂, where R⁹ to R¹⁴ are identical or different and may becovalently linked to one another, R²⁵ and R²⁶ are each hydrogen or asubstituted or unsubstituted, aliphatic or aromatic hydrocarbon radicalhaving from 1 to 25 carbon atoms, and may be identical or different, Mis an alkali metal, alkaline earth metal, ammonium or phosphonium ionand R¹, R², R³, R⁴ and Q have the meanings and provisos state inclaim
 1. 14. A bisphosphite-metal complex as claimed in claim 10,wherein W and X are each a aromatic hydrocarbon radical having from 1 to50 carbon atoms which are covalently linked as in formula VI

wherein R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are each hydrogen, analiphatic, alicyclic, aliphatic-alicyclic, heterocyclic,aliphatic-heterocyclic, aromatic, aromatic-aromatic, aliphatic-aromatichydrocarbon radical having from 1 to 50 carbon atoms, F, Cl, Br, I,—CF₃, —OR²⁵, —COR²⁵, —CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃R²⁵,—SO₃M, —SO₂NR²⁵R²⁶, NR²⁵R²⁶, N═CR²⁵R²⁶, NH₂, where R⁹ to R¹⁶ areidentical or different and may be covalently linked to one another, R²⁵and R²⁶ are each hydrogen or a substituted or unsubstituted, aliphaticor aromatic hydrocarbon radical having from 1 to 25 carbon atoms, andmay be identical or different, M is an alkali metal, alkaline earthmetal, ammonium or phosphonium ion and R¹, R², R³, R⁴ and Q have themeanings and provisos stated in claim
 1. 15. A bisphosphite-metalcomplex as claimed in claim 11, wherein W and X are aliphatic,alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic,aromatic, aromatic-aromatic, aliphatic-aromatic hydrocarbon radicalshaving from 1 to 50 carbon atoms which are covalently linked as informula V

and R¹, R², R³, R⁴ and Q have the meanings and provisos stated in claim7.
 16. A bisphosphite-metal complex as claimed in claim 11, wherein Wand X are each a aromatic hydrocarbon radical having from 1 to 50 carbonatoms which is covalently linked as in formula VI

wherein R⁹, R¹⁰, R¹¹, R¹², R¹³ and R¹⁴ are each hydrogen, an aliphatic,alicyclic, aliphatic-alicyclic, heterocyclic, aliphatic-heterocyclic,aromatic, aromatic-aromatic, aliphatic-aromatic hydrocarbon radicalhaving from 1 to 50 carbon atoms, F, Cl, Br, I, —CF₃, —OR²⁵, —COR²⁵,—CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃R²⁵, —SO₃M, —SO₂NR²⁵R²⁶,NR²⁵R⁶, N═CR²⁵R²⁶, NH₂, where R⁹ to R¹⁴ are identical or different andmay be covalently linked to one another, R²⁵ and R²⁶ are each hydrogenor a substituted or unsubstituted, aliphatic or aromatic hydrocarbonradical having from 1 to 25 carbon atoms, and may be identical ordifferent, M is an alkali metal, alkaline earth metal, ammonium orphosphonium ion and R¹, R², R³, R⁴ and Q have the meanings and provisosstate in claim
 1. 17. A bisphosphite-metal complex as claimed in claim11, wherein W and X are each a aromatic hydrocarbon radical having from1 to 50 carbon atoms which are covalently linked as in formula VII

wherein R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are each hydrogen, analiphatic, alicyclic, aliphatic-alicyclic, heterocyclic,aliphatic-heterocyclic, aromatic, aromatic-aromatic, aliphatic-aromatichydrocarbon radical having from 1 to 50 carbon atoms, F, Cl, Br, I,—CF₃, —OR²⁵, —COR²⁵, —CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃R²⁵,—SO₃M, —SO₂NR²⁵R²⁶, NR²⁵R²⁶, N═CR²⁵R²⁶, NH₂, where R⁹ to R¹⁶ areidentical or different and may be covalently linked to one another, R²⁵and R²⁶ are each hydrogen or a substituted or unsubstituted, aliphaticor aromatic hydrocarbon radical having from 1 to 25 carbon atoms, andmay be identical or different, M is an alkali metal, alkaline earthmetal, ammonium or phosphonium ion and R¹, R², R³, R⁴ and Q have themeanings and provisos stated in claim
 1. 18. A bisphosphite-metalcomplex as claimed in claim 10, wherein Q is a hydrocarbon radical ofthe formula VIII

where R¹⁷, R¹⁸, R¹⁹, R²⁰, R²¹, R²², R²³ and R²⁴ are each hydrogen, analiphatic, alicyclic, aliphatic-alicyclic, heterocyclic,aliphatic-heterocyclic, aromatic, aromatic-aromatic, aliphatic-aromatichydrocarbon radical having from 1 to 50 carbon atoms, F, Cl, Br, I,—CF₃, —OR²⁵, —COR²⁵, —CO₂R²⁵, —CO₂M, —SR²⁵, —SO₂R²⁵, —SOR²⁵, —SO₃R²⁵,—SO₃M, —SO₂NR²⁵R²⁶, NR²⁵R²⁶, N═CR²⁵R²⁶, NH₂, where R¹⁷ to R²⁴ areidentical or different and may be covalently linked to one another, R²⁵and R²⁶ are each hydrogen or an substituted or unsubstituted, aliphaticor aromatic hydrocarbon radical having from 1 to 25 carbon atoms, M isan alkali metal, alkaline earth metal, ammonium or phosphonium ion, andpositions a and b are linkage points.
 19. A bisphosphite-metal complexas claimed in claim 10, wherein the metal is rhodium, platinum, cobaltor ruthenium.
 20. A method for the hydroformylation of olefins,comprising: hydroformylating an olefin reactant under hydroformylationconditions in the presence of a bisphosphite-metal complex as claimed inclaim
 1. 21. A method for the hydroformylation of olefins, comprising:hydroformylating an olefin reactant under hydroformylation conditions inthe presence of a bisphosphite-metal complex formed from a combinationof the bisphosphite of claim 1 and another metal complexing phosphorusligand.
 22. The method according to claim 20, wherein the olefinreactant is propene, 1-butene, cis-2-butene, trans-2-butene, isobutene,butadiene, mixtures of C₄-olefins, 1- or 2-pentene, 2-methyl-1-butene,2-methyl-2-butene, 3-methyl-1-butene, 1-, 2- or 3-hexene, the C₆-olefinmixtures formed in the dimerization of propene (dipropene), 1-heptene,heptenes, 2- or 3-methyl-1-hexene, 1-octene, octenes, 2-methylheptenes,3-methylheptenes, 5-methyl-2-heptene, 6-methyl-2-heptene,2-ethyl-1-hexene, the isomeric Cg-olefin mixtures formed in thedimerization of butenes (dibutene), 1-nonene, nonenes, 2- or3-methyloctenes, the C₉-olefin mixtures formed in the trimerization ofpropene (tripropene), decenes, 2-ethyl-1-octene, dodecenes, theC₁₂-olefin mixture formed in the tetramerization of propene or thetrimerization of butenes (tetrapropene or tributene), tetradecene,hexadecenes, the C₁₆-olefin mixtures formed in the tetramerization ofbutenes (tetrabutene) and olefin mixtures prepared by co-oligomerizationof olefins having different numbers of carbon atoms.